This invention relates to the formation of twin sheet hollow plastic articles, and more particularly to the formation of twin sheet plastic pallets.
Pallets have traditionally been formed of wood. Wood pallets however have many disadvantages. For example, they are subject to breakage and thus are not reusable over an extended period of time. Wood pallets also take up a considerable amount of valuable space in the warehouse when they are not in use. In an effort to solve some of the problems associated with wood pallets, plastic pallets have been developed and employed with varying degrees of success. One form of highly successful plastic pallet embodies a twin sheet construction in which an upper plastic sheet is thermal formed over a male mold having downwardly extending leg protrusions, a lower plastic sheet is thermal formed over a female mold having leg cavities complemental to the leg protrusions on the male mold, and the sheets are selectively fused together with the hollow leg protrusions of the upper sheet nested in the hollow leg cavities of the lower sheet to form a plastic pallet having a generally planar platform structure and a plurality of spaced hollow fused legs extending downwardly from the platform structure and opening in the upper face of the platform structure.
Whereas this twin sheet pallet has been highly successful and has been widely commercialized, this pallet is significantly more expensive than a comparable wooden pallet.